Conventionally, whole blood transfusion in which all the components of blood obtained by blood donation are put to transfusion has been common practice. With the recent progress of technology, blood component transfusion has come to be carried out in which the blood obtained is separated into its components such as red blood cells, platelets and plasma and only the component(s) necessary for a patient is transfused into the patient. Using blood component transfusion, the burden on the patient's circulatory system and side effects can be alleviated, and generally effective utilization of donated blood can be achieved.
The blood (whole blood) obtained by blood donation is centrifuged to be thereby separated into a light supernatant PPP (platelet poor plasma) fraction, a heavy precipitated CRC (concentrated red cell) fraction, and buffy coat therebetween. The buffy coat contains leukocytes, platelets and red cells; especially, as for platelets, the proportion of young fresh platelets is high.
In order to separate whole blood into the three blood components including platelet poor plasma, concentrated red cells and buffy coat, and further to transport the blood components into predetermined storage bags, there has hitherto been used a blood bag system configured by connecting a plurality of bags using a plurality of tubes. An example is disclosed in U.S. Pat. No. 6,910,998.
One conventional example of a blood bag system includes a first bag (combined buffy coat bag and whole blood bag) for storing whole blood, a first tube connected at its one end to an upper portion of the first bag, a second bag (plasma bag) which is connected to the other end of the first tube and in which platelet poor plasma is to be stored, a second tube connected at its one end to a lower portion of the first tube, and a third bag (red cell bag) which is connected to the other end of the second tube and in which concentrated red cells are to be stored. In order to preserve whole blood in the state of being separated into the blood components by use of the blood bag system configured as just-mentioned, the whole blood in the first bag is centrifuged to be separated into platelet poor plasma, concentrated red cells and buffy coat, and, thereafter, the platelet poor plasma is transported to the second bag through the first tube connected to an upper portion of the first bag, and the concentrated red cells are transported to the third bag through the second tube connected to a lower portion of the first bag.
The specification of U.S. Pat. No. 6,910,998 discloses a blood bag system similar to the one conventional example mentioned above.
A centrifuging and transporting apparatus which permits a step of centrifuging whole blood and a step of transporting blood components obtained by centrifugation to be performed by a single apparatus may be configured to include a centrifugal drum having a plurality of unit insertion holes and driven to rotate in a circumferential direction and a plurality of insert units to be inserted in the unit insertion holes. An example is disclosed in U.S. Pat. No. 6,910,998. In this case, the insert unit permits the above-mentioned blood bag system to be mounted thereto.
When the above-mentioned blood bag system is supposed to be mounted to the centrifuging and transporting apparatus configured as above, difficulties can arise. A first bag in the above-mentioned blood bag system has a top-and-bottom (TAB) type bag structure in which a first tube is connected to an upper portion thereof and a second tube is connected to a lower portion thereof. Therefore, in mounting the first tube to the above-mentioned insert unit, the second tube provided at the lower portion of the first bag must be laid around upward from the lower side (bottom side) of the insert unit, and the handling operation is bothersome, so that it is difficult to smoothly carry out the mounting operation. In addition, if the second tube undergoes kinking (torsion or sharp bending) due to the handling of the second tube, the second tube may be closed, possibly making it impossible to transport blood components.